1. Field of the Invention
This invention relates generally to latch-bolt mechanisms, and more particularly to a duplex latch-bolt mechanism that can be adapted to any door fitting arrangement by mere adjustment--i.e., without requiring any mechanical modification (drilling, cutting or bending).
2. Prior Art
At present there are two kinds of backset configurations in the structure of traditional latch-bolt mechanisms--namely, a 23/8 inch type and a 23/4 inch type. In order to meet the configuration requirements of these two types of latch-bolt mechanism, two types of door locks are produced.
As ordinary consumers, however, are unaware of this situation, a great deal of inconvenience is caused in the installation of door locks; different latch-bolt mechanisms are required by different lock-fitting arrangements of doors.
Moreover, different molding sets have to be prepared by the lock manufacturers for producing the different latch-bolt mechanisms, resulting in increased manufacturing costs. Also, it is inconvenient for lock dealers to prepare the different parts lists and storage spaces to put the different latch-bolt mechanisms on sale.